UFO Landing or What?

It was in the mid-80's. Some UFO fanatics told me that UFOs cause disturbances in the Earth's magnetic field when they travel by. That should be measurable, I thought, and put together a small, simple measuring device. As usual, the UFO people weren't able to come up with any concrete measurement data, time data or information about field strengths, so I had to make some guesses.

Having a sensor connected to a strip chart recorder, it would be possible to make long duration measurements and try to discover any peculiarities, repeating patterns and so on. Keep in mind that this was long before anyone would think about letting a PC collect the data and compile a report on it. I built the equipment at work and let the recorder stay on all night, just for testing, and was lucky enough to register something unusual. Or, perhaps it was nothing...

Equipment

What was needed was a sensitive enough sensor. At home, in a a closet, I found a 20,000 turn coil with a 6 centimetres outer diameter and a 2 centimetre hole in the middle. I stuck the hole full of 5 inch iron nails, increasing the sensitivity many times (amazingly, we had no hum in the building). The coil was connected directly to the input of the recorder and was put on a stable foundation. The smallest of movements resulted in wild fluctuations, as the coil was turning in the Earth's magnetic field.

Measurement Results

Below is the strip chart that came out of the recorder that very night, and to the right are my comments about the marked-up events. To the right on the strip I have put the approximate times (reconstruction).

A. Some tests, before I got everything right. B. Rattling a key ring a few decimetres from the coil gave some very large fluctuations. C. It's getting time to go home. People are closing doors, perhaps car doors in the car park, running machines that take a lot of current, etc. There was no lift in the house. D. The noise level decreases. Everyone has more or less left the building, so the man-made magnetic noise fields are decreasing. E. Perhaps cars, passing in the street outside? F. And then, at about 1 o'clock in the night, it happens! What? Well, it's anyone's guess. It had to be something big. A UFO landing? Vagabond currents coming up through our lab? A micro earthquake, that made the coil shake a little? It wasn't the solar wind, I have checked up on that. The house was empty, and we didn't have a night watchman. G. It's morning, and the noise and disturbances begin to increase. H. Everyone's working again. The noise reaches top level, after the morning coffee break.

Equipment Used

Equipment	Specification
Strip chart recorder	3 channel pen recorder YEW (Yokogawa Electric Works Ltd.) Type 3065 Pen Recorder. Measuring ranges: 5 uV/cm to 5V/cm 1 cm/s to 2 cm/h Set for 1 mV/cm. Only one channel was used.
Measuring coil	20,000 turns of copper wire on an iron core, fastened to a wooden shelf with tape.